No Start.

[The Dat-side]

So first off: 510, L20B, inter-regu 50amp alt, (new)battery relocated to trunk.

Day 1- Car won't start. Jump terminals on the starter with a screwdriver and it goes. The rest of the day it does fine starting with the key.

Day 2- Have to start it with the screwdriver. Drive to school. It sits for 5 hours and starts right back up with the key.

Day 3- Work

Day 4- Work

Day 5- Have the starter tested and it passes but kinda weak. New starter is tested and works great. Now it slowly/weakly turns but doesn't start.

 

Any ideas? Bad ground? All battery and starter terminals are amazingly clean!

[datzenmike]

A common problem with the 510 is a weak 12 volt start signal from the ignition switch. It's the small black yellow wire on the starter. Could be loose or corroded but likely just old wiring. The battery has to go all the way to the ignition and back to the starter on small wires with lots ov voltage drop. Instead of 12 volts it's moer like 5-8 volts and not strong enough to power the starter solenoid.

 

Before investing the time on the following I would verify a weak start signal by using a volt meter on the disconnected Black/Yellow wire at the starter.

 

You could try running a larger gauge wire back to the ignition switch.

 

or...

 

Use the weak start signal to trigger a relay that provides a 12 volt directly from the battery. I did this on my 710. I measured about 5-6 volts for the start signal which is way more than enough to trigger a cheap Nissan relay from a 720. Starting always took 2-6 key turns before the starter would kick in.

 

Connect the start signal from the ignition to one side of the coil on the relay below. Terminal one (or two) and ground the other. When the key is in the start position power flows through the coil to ground energizing it and connects terminals three and five. Find a 12 volt battery source and connect to three (or five) and the other one to the starter.

 

 

 

I was able to find my start signal wire, a 12 source and a ground here under the plastic box on the fender. Made all the connections, soldered them and taped them up nice and neat. The box covers and keeps the weather out. The starter has never failed to turn on the first try since doing this simple cure. You can see the blue relay and the shrink wrap tubing on the wires I connected. below

 

 

Everything tucked away under the 'black box'.

 

 

 

.

[The Dat-side]

Thanks Mike, I'll keep that in mind.

 

Turns out the PO didn't ground the starter after relocating the battery. Simply attaching a jumper cable to the starter bolt and then to the strut bolt it started right up. I've had the car for like 9 mos or something and now have trouble with it. Who knows how long ago the battery was relocated.

Now any suggestions of grounding the starter? I was told strait to the frame will just make it rust quicker.

[DISLEXICDIME]

Thanks Mike, I'll keep that in mind.

 

Turns out the PO didn't ground the starter after relocating the battery. Simply attaching a jumper cable to the starter bolt and then to the strut bolt it started right up. I've had the car for like 9 mos or something and now have trouble with it. Who knows how long ago the battery was relocated.

Now any suggestions of grounding the starter? I was told strait to the frame will just make it rust quicker.

 

is the block grounded to the body?

[datzenmike]

Normally the ground wire from the battery goes to the bolt on the head just behind the fuel pump. I assume the PO just bolted to the body??? Wow,.... just wow. The drive train is rubber mounted to reduce vibration.... and this also isolates it somewhat electrically. Heavy current draw has to travel down the throttle linkage or something else like the fuel lines? to get to the starter on the block.

 

Best would be to run a battery cable forward to the transmission case at the rear mount bolt. (the starter is bolted to the tranny so this would be a perfect ground) Alternatively, a battery cable connecting the body sheet metal to the block or transmission will work. Has to be thick as a battery cable to handle the hundreds of amps current flow when cranking.

[The Dat-side]

is the block grounded to the body?

Not ATM but tomorrow it will be.

 

Normally the ground wire from the battery goes to the bolt on the head just behind the fuel pump. I assume the PO just bolted to the body??? Wow,.... just wow. The drive train is rubber mounted to reduce vibration.... and this also isolates it somewhat electrically. Heavy current draw has to travel down the throttle linkage or something else like the fuel lines? to get to the starter on the block.

 

Best would be to run a battery cable forward to the transmission case at the rear mount bolt. (the starter is bolted to the tranny so this would be a perfect ground) Alternatively, a battery cable connecting the body sheet metal to the block or transmission will work. Has to be thick as a battery cable to handle the hundreds of amps current flow when cranking.

 

Kinda what I was thinking Mike.